New malware has the ability to evade popular sandboxes

A new piece of malware linked to the widespread destruction and bank account plundering has
become even nastier with the ability to evade popular sandboxes, says Seculert CTO Aviv Raff.

Raff says the Dyre malware ducks popular sandbox tools by detecting the number of cores in
its use.

The known but effective and previously unused technique is enough to beat at least eight of
the most widely used free and commercial software, Raff says.

"If the machine has only one core it immediately terminates," Raff said in a blog post.

"As many sandboxes are configured with only one processor with one core as a way to save resources,
the check performed by Dyre is a good and effective way to avoid being analysed.

"On the other hand, most of the PCs in use today have more than one core." Dyre is linked to
a variant Dyre Wolf that IBM said last month plundered some $1 million from bank accounts.

Raff informed the affected sandbox developers of the evasion technique. Dyre's Upatre downloader
also sports new evasion techniques including a different user agent and grammatical fixes previously
used to identify the malware.

Raff says the technique proves that sandboxing should not be used in isolation to stamp out
malware.

It is the latest development in a long history of cat-and-mouse warfare between malware writers
and white hat defenders.

Criminals need to contend with infiltrating victim machines while avoiding anti-virus and white
hats who look for indicators that are hallmarks of a type of malware.